bateries????

[T-water]

I have a 12v trolling motor. This spring I charged my trolling battery. The next morning I turned it off and tested it, the motor gauge said it was at 100% about 3 days later I tried it again and the gauge said it was at 75%, what happened is the motor past it's prime? I also tried this with another battery (1Year newer) same thing happened the power drained after a few days...thoughts recommendations.

[john.wells]

Those gages aren't terribly accurate, more of an indicator. The only true way to test battery is with a multimeter. Batteries do lose voltage from just sitting, and if you have something connected to the terminals, there could be what is called "parasitic drain" A good example is the memory of a car stereo for time/presets. There is an almost unnoticable drain from these, but over time it taps the juice. Other possibilities are: you didn't charged the battery for long enough; the battery is getting old; the battery may have frozen; the battery has been overcharged.

[T-water]

Thanks John

No parasites here! I'm going to guess the battery is past it's prime. Time to buy some new batteries. Where do you guys buy batteries?

[BobT]

To test a battery using a VOM is not accurate either unless you put it under load. It doesn't take much to show full voltage potential but current delivery is another thing altogether. Before forking out for a new battery, I recommend you take it in for a load test. You can also pick up a tester at a local auto parts store rather inexpensively and test the specific gravity of the cells to see how they are doing. Just follow the instructions.

Bob